Tobacco filling for non-combustion-type heating smoking article

ABSTRACT

The present invention provides a tobacco raw material having a good inhalation flavor and a method for manufacturing same. Provided is a tobacco raw material in which the ratio of the weight of extracts obtained by extraction using n-hexane as a solvent to the weight of extracts obtained by further extraction using water as a solvent after the abovementioned extraction is a water-extracted weight/hexane-extracted weight ratio of 0-1.5.

TECHNICAL FIELD

The present invention relates to a tobacco filler for a non-combustion smoking article that fills a non-combustion smoking article for use.

BACKGROUND ART

In recent years, non-combustion smoking articles that replace cigarettes and allow experience of a smoke flavor without combusting tobacco have been developed, and one in which a smoke flavor component and a component capable of generating aerosol fill a pod-shaped container for use or one having a heat source at a tip thereof is typically known.

It has been also reported that an acid is added to a filler in such non-combustion smoking articles (see PTL 1 to 3).

CITATION LIST Patent Literature

[Patent Literature 1] WO 2014/190079

[Patent Literature 2] U.S. Patent Application Publication No. 2015/0020820 (Specification)

[Patent Literature 3] U.S. Patent Application Publication No. 2014/0345631 (Specification)

SUMMARY OF INVENTION Technical Problem

During smoking with non-combustion smoking articles, the amount of evaporation of smoke flavor components may be insufficient compared to that from cigarettes or a user may feel so-called “smoke flavor inhibition”.

An object of the present invention is to provide a tobacco filler for a non-combustion smoking article that can suppress a reduction in an amount of evaporated smoke flavor components and suppress “smoke flavor inhibition” in a non-combustion smoking article, particularly a smoking article in which a filler containing shredded tobacco is heated.

Solution to Problem

The inventors of the present invention carried out an extensive study in order to solve the problem and, as a result, found that by adding an acid fulfilling specific conditions to a tobacco filler, a reduction in the amount of evaporated smoke flavor components may be suppressed and “smoke flavor inhibition” may be suppressed, thereby completing the present invention.

Thus, the present invention is as follows.

<1> A tobacco filler for a non-combustion smoking article containing shredded tobacco, and liquid that generates aerosol, wherein

the tobacco filler contains an acid that has a first acid dissociation constant of 4.0 to 6.0 inclusive and a boiling point of 366° C. to 600° C. inclusive.

<2> The tobacco filler according to <1>, wherein the acid is at least one selected from the group consisting of ascorbic acid, isoascorbic acid, heneicosanoic acid, lignoceric acid, octacosanoic acid and nonadecanoic acid.

<3> The tobacco filler according to <1> or <2>, containing the acid at 0.25% by mass to 10% by mass inclusive of the whole tobacco filler.

<4> The tobacco filler according to any of <1> to <3>, wherein the liquid that generates aerosol contains propylene glycol (PG).

Advantageous Effects of Invention

According to the present invention, a reduction in the amount of evaporated smoke flavor components may be suppressed and “smoke flavor inhibition” may be suppressed in a non-combustion smoking article in which a filler containing shredded tobacco is heated.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a section view illustrating an example of a non-combustion smoking article.

FIG. 2 is a graph illustrating the relationship between the first acid dissociation constant of acid and the amount of evaporated smoke flavor components.

FIG. 3 is a graph illustrating the relationship between the boiling point of acid having a first acid dissociation constant of 4.0 to 6.0 inclusive and smoke flavor inhibition.

FIG. 4 is a graph illustrating the relationship between the boiling point of acid having a first acid dissociation constant of 4.0 to 6.0 inclusive and chemical odor.

FIG. 5 is a graph illustrating the relationship between the acid content and smoke flavor inhibition.

FIG. 6 is a graph illustrating the relationship between the type of liquid that generates aerosol and smoke flavor inhibition.

DESCRIPTION OF EMBODIMENT

The present invention is described by way of specific examples. However, the present invention is not limited to the following content, and may be appropriately modified and practiced without departing from the scope of the present invention.

<Tobacco Filler for a Non-Combustion Smoking Article>

The tobacco filler (hereinafter abbreviated as “tobacco filler of the present invention”) for a non-combustion smoking article according to one embodiment of the present invention contains shredded tobacco, and liquid that generates aerosol, and is characterized in that the tobacco filler contains an acid that has a first acid dissociation constant of 4.0 to 6.0 inclusive and a boiling point of 366° C. to 600° C. inclusive.

The inventors of the present invention have revealed various issues on non-combustion smoking articles, particularly smoking articles in which a filler containing shredded tobacco is heated.

For example, when an acid is added to a filler (which generally contains liquid that generates aerosol) containing shredded tobacco, the amount of evaporated smoke flavor components may be reduced. This may be caused by penetration of added acid into shredded tobacco together with liquid that generates aerosol and formation of salts with smoke flavor components in shredded tobacco. In non-combustion smoking articles which are heated to high temperature, salts may be dissociated by heating or a reduction in the amount of evaporated smoke flavor components may be suppressed due to high temperature, while the influences may be significant in non-combustion smoking articles which are heated to low temperature.

During smoking using non-combustion smoking articles, users may feel “smoke flavor inhibition” such as receiving a stimulus that is different from tobacco or generating physiological spontaneous actions such as “choking”. This may be caused by components that inhibit smoke flavor in a filler, and volatilization of the components together with solvents such as propylene glycol may cause “smoke flavor inhibition”.

The inventors of the present invention revealed that formation of salts from acids and smoke flavor components in shredded tobacco is correlated with the first acid dissociation constant (pKa₁) representing the strength of acid and formation of salts may be suppressed by selecting an acid having a first acid dissociation constant within a specific range, and less chemical odor (chemical smell) or the like may be sensed by selecting an acid having a boiling point at or above a certain temperature. Namely, the inventors of the present invention found that by adding an “acid that has a first acid dissociation constant of 4.0 to 6.0 inclusive and a boiling point of 366° C. to 600° C. inclusive” to a tobacco filler, a reduction in the amount of evaporated smoke flavor components may be suppressed and “smoke flavor inhibition” may be suppressed.

The “first acid dissociation constant” means an acid dissociation constant in water at normal temperature (25° C.)

The “boiling point” means a boiling point at pressure of 760 mmHg.

The “non-combustion smoking article”, “shredded tobacco”, “liquid that generates aerosol”, “acid that has a first acid dissociation constant of 4.0 to 6.0 inclusive and a boiling point of 366° C. to 600° C. inclusive” and the like are hereinafter specifically described.

The tobacco filler of the present invention is a tobacco filler for a non-combustion smoking article containing shredded tobacco, and liquid that generates aerosol. The non-combustion smoking article which is filled with the tobacco filler of the present invention is not particularly limited as to the specific structure and the like thereof, and may appropriately be any well-known non-combustion smoking article. The non-combustion smoking article is hereinafter described by way of specific examples.

Examples of the non-combustion smoking article include the one that has the structure as a non-combustion smoking article 10 illustrated in FIG. 1. FIG. 1 is a section view of the cylindrical non-combustion smoking article 10 along the longitudinal direction. The non-combustion smoking article 10 has the structure having a battery 101, a pod 103 that accommodates a filler 102 and a heater 104 and a mouthpiece 105. By filling the pod 103 with the tobacco filler of the present invention and heating the same, aerosol is generated.

The heating temperature of the tobacco filler in the non-combustion smoking article is generally 22° C. or higher, preferably 100° C. or higher and more preferably 150° C. or higher, and generally 350° C. or lower, preferably 300° C. or lower and more preferably 250° C. or lower. The non-combustion smoking article having a heating temperature of a tobacco filler within the above range tends to have an issue of “smoke flavor inhibition”, and thus characteristics of the tobacco filler of the present invention may be more efficiently exploited.

Examples of the type of the shredded tobacco include flue-cured tobacco, Burley tobacco, Japanese domestic tobacco, regenerated tobacco and the like. Examples of the region used include the leaf (expanded tobacco), stem, rib (cut stem), root, flower and the like.

The dimension of the shredded tobacco is not particularly limited. The shredded tobacco preferably has a sphere equivalent diameter of generally 1.5 mm or less and preferably 0.5 mm or less and generally 0.01 mm or more as measured by a projected sectional-area method (such as the method using Camsizer (Retsch Technology GmbH)).

The tobacco filler of the present invention contains shredded tobacco at generally 20% by mass or more, preferably 30% by mass or more and more preferably 40% by mass or more, and generally 80% by mass or less, preferably 70% by mass or less and more preferably 60% by mass or less. The content within the above range allows easier suppression of a reduction in the amount of evaporated smoke flavor components and more effective suppression of “smoke flavor inhibition”.

Examples of the liquid that generates aerosol include polyhydric alcohols such as glycerol, propylene glycol, triethylene glycol and tetraethylene glycol; aliphatic esters of carboxylic acids such as methyl stearate, dimethyl dodecanedioate and dimethyl tetradecanedioate and the like. The liquid used is not limited to one type and may be a combination of two or more.

The liquid that generates aerosol preferably contains propylene glycol. Propylene glycol is used for food and medicinal products as a highly safe solution and can easily generate visible smoke because of the low boiling point and liability of vaporisation. Meanwhile, propylene glycol has high vapour pressure, and thus is liable to volatilise in the oral cavity. Because of this, propylene glycol may create an atmosphere in which components inhibiting smoke flavor contained in aerosol are liable to volatilise, thereby more easily causing an issue of “smoke flavor inhibition”. Consequently, characteristics of the tobacco filler of the present invention may be more efficiently exploited.

The tobacco filler of the present invention contains liquid that generates aerosol at generally 20% by mass or more, preferably 30% by mass or more and more preferably 40% by mass or more, and generally 80% by mass or less, preferably 70% by mass or less and more preferably 60% by mass or less. The content within the above range allows easier suppression of a reduction in the amount of evaporated smoke flavor components and more effective suppression of “smoke flavor inhibition”.

The tobacco filler of the present invention is characterised in that the tobacco filler contains an acid that has a first acid dissociation constant of 4.0 to 6.0 inclusive and a boiling point of 366° C. to 600° C. inclusive (hereinafter also abbreviated as “acid”). Specific acids are not particularly limited as far as the acids fulfil the conditions and well-known acids may be appropriately used according to the purpose. Specific examples are hereinafter described.

The acid has a first acid dissociation constant of preferably 4.5 or more and preferably 5.5 or less.

The acid has a boiling point of preferably 400° C. or higher and preferably 560° C. or lower.

The first acid dissociation constant and the boiling point within the above ranges allows more effective suppression of “smoke flavor inhibition”.

Examples of the acid include ascorbic acid, isoascorbic acid, heneicosanoic acid, lignoceric acid, octacosanoic acid, nonadecanoic acid and the like.

Among others, ascorbic acid and isoascorbic acid are particularly preferred.

The acid as described above allows easier suppression of a reduction in the amount of evaporated smoke flavor components and more effective suppression of “smoke flavor inhibition”.

The tobacco filler of the present invention contains the acid at generally 0.25% by mass or more and preferably 1% by mass or more and generally 10% by mass or less. The content within the above range allows easier suppression of a reduction in the amount of evaporated smoke flavor components and more effective suppression of “smoke flavor inhibition”.

The tobacco filler of the present invention contains shredded tobacco, and liquid that generates aerosol. Generally, components contained in shredded tobacco such as water elute in the liquid that generates aerosol, and thus it can be regarded that the tobacco filler of the present invention also contains water.

The tobacco filler of the present invention contains water at generally 5% by mass or more, preferably 7.5% by mass or more and more preferably 10% by mass or more, and generally 30% by mass or less, preferably 25% by mass or less and more preferably 20% by mass or less of the whole tobacco filler. The content within the above range allows easier suppression of a reduction in the amount of evaporated smoke flavor components and more effective suppression of “smoke flavor inhibition”.

EXAMPLES

The present invention is more specifically described by way of Examples. The present invention may be appropriately modified within the scope of the present invention.

Examples 1 to 6, Comparative Examples 1 to 21: Effect by First Acid Dissociation Constant and Boiling Point of Acids

To shredded flue-cured tobacco (produced in Japan, 100 mg), 100 mg of liquid obtained by mixing propylene glycol and glycerol at 1:1 (weight ratio) was added and the acid indicated in Table 1 was added at 5% by mass in terms of the mass of the whole composition, thereby preparing a sample. Shredded tobacco used was obtained by grinding tobacco in a household mixer followed by shaking on a sieve (AS200, manufactured by Retsch Technology GmbH) under the condition: amplitude-1.5 mm/“g” for 2 minutes, and had a mesh size of 0.5 mm or less.

The prepared sample was placed so as to attach to a pod dedicated to a product with the product name “Ploom®” marketed by Japan Tobacco Inc., and stored for 2 days or more under the conditions of 22° C. and humidity of 60%. It was verified that the heating temperature (during stable operation) of shredded tobacco using Ploom was about 160° C. to 170° C. by preliminary measurement using a thermocouple.

In smoking test, the prepared pod was attached to Ploom and the amount of evaporated smoke flavor components during initial 10 puffs was measured under specified smoking conditions (55 ml/2 s, smoking interval: 30 s) on a smoking machine (Borgwaldt, RM-26). In the present experiment, the indicative component selected was nicotine, which can be easily measured as a smoke flavor component. Smoke was trapped with a Cambridge filter pad, the smoke trapped on the filter was extracted in a methanol solvent while shaking for 40 minutes and nicotine was assayed by GC-FID.

The sensory evaluation of the smoking test was carried out by four evaluators and “smoke flavor inhibition” and “chemical odor” as the taste of acid were evaluated on a 7-grade scale of 1 to 7. “Chemical odor” means the smell of chemicals and is unwanted odor during smoking by human beings. The higher the score is, the stronger the chemical odor is. In the results of the present Examples, it was regarded that the region in which the evaluated scores on smoke flavor inhibition and chemical odor were 2 or less was a region with an excellent effect in which evaluators could sufficiently recognize the difference. The evaluation was made and written down according to the sensation during smoking.

The physical values of acids, the amount of evaporated smoke flavor component and the results of the sensory test are respectively indicated in Table 1.

TABLE 1 Type and physical values of acids and evaluation results Amount of evaporated smoke Type of acid, physical values flavor components Boiling Point Acid dissociation Smoke flavor Chemical (nicotine, in this case) Classification Name [°C.] constant pKa₁ inhibition odor [mg/10 puffs] Comparative Example 1 No addition No addition — — 3.8 1.7 0.25 Comparative Example 2 Inorganic Phosphoric acid 213 1.97 1.0 2.0 0.04 acid Comparative Example 3 Aromatic Benzoic acid 249 4.21 4.3 4.2 0.21 Comparative Example 4 Carboxylic Cinnamic acid 300 4.44 3.1 5.3 0.14 acid Comparative Example 5 Aliphatic Acetic acid 118 4.76 4.3 4.8 0.23 Comparative Example 6 Carboxylic Decanoic acid 269 4.90 2.0 6.7 0.23 Comparative Example 7 acid Lauric acid 299 5.20 2.2 5.8 0.22 Comparative Example 8 Myristic acid 326 ≈5.00 1.5 6.2 0.23 Comparative Example 9 Palmitic acid 351 1.8 3.0 0.28 Comparative Example 10 Stearic acid 361 2.2 1.5 0.21 Example 1 Heneicosanoic acid 384 2.0 1.3 0.27 Example 2 Lignoceric acid 406 1.7 1.7 0.24 Example 3 Octacosanoic acid 431 2.0 1.5 0.26 Comparative Example 11 Unsaturated Linolenic acid 365 2.8 2.5 0.19 Example 4 Carboxylic Nonadecanoic acid 368 1.9 2.0 0.22 Comparative Example 12 acid Sorbic acid 228 4.76 4.0 2.8 0.22 Comparative Example 13 Hydroxy Citric acid 175 3.09 1.7 3.3 0.07 Comparative Example 14 acid Lactic acid 122 3.86 1.7 2.3 0.11 Comparative Example 15 Oxalic acid 150 1.27 1.3 5.3 0.04 Comparative Example 16 Tartaric acid 399 3.22 2.0 2.8 0.05 Comparative Example 17 Succinic acid 235 4.20 1.3 2.3 0.14 Comparative Example 18 Fumaric acid 290 3.03 1.3 3.5 0.05 Comparative Example 19 Malic acid 322 3.40 2.6 3.7 0.08 Comparative Example 20 Keto Levulinic acid 245 4.44 1.3 3.0 0.23 Comparative Example 21 acid Pyruvic acid 165 2.50 1.2 3.8 0.17 Example 5 Other Ascorbic acid 553 4.17 1.3 1.7 0.20 Example 6 Isoascorbic acid 503 4.13 1.5 2.0 0.21

FIG. 2 indicates a graph illustrating the relationship between the first acid dissociation constant of acids and the amount of evaporated smoke flavor components. From FIG. 2, it resulted that acids having low first acid dissociation constant had low amounts of smoke flavor components, and for most of acids having an acid dissociation constant of 4.0 or more, the amounts of smoke flavor components were equivalent to the amount of smoke flavor components without addition of acid. From this result, it was found that by using an acid having a first acid dissociation constant of 4.0 or more, the amount of evaporated smoke flavor components does not decrease. As most of acids have a first acid dissociation constant or 6.0 or less by taking the pH of acids into account, the ideal range of the first acid dissociation constant is 4.0 to 6.0 inclusive.

FIG. 3 indicates a graph illustrating the relationship between the boiling point of acids having a first acid dissociation constant of 4.0 to 6.0 inclusive and smoke flavor inhibition. It was found that at a boiling point of 366° C. or higher, smoke flavor inhibition could be reduced with almost all acids, and thus the boiling point was important for reduction of smoke flavor inhibition.

FIG. 4 indicates a graph illustrating the relationship between the boiling point of acids having a first acid dissociation constant of 4.0 to 6.0 inclusive and chemical odor. It was found that chemical odor decreased with acids having a boiling point of 366° C. or higher. When the boiling point of acid is too high, the amount of acid released by heating decreases, and thus it is believed that the boiling point is preferably 600° C. or lower.

From the above, under the conditions where the amount of smoke flavor components kept constant, use of an acid that has a first acid dissociation constant of 4.0 to 6.0 inclusive and a boiling point of 366° C. to 600° C. inclusive had low effects on the taste and flavor and could reduce smoke flavor inhibition.

Examples 7 to 12: Effect by Acid Content

The test was carried out in the same manner as in previous Examples except that the contents of acids, isoascorbic acid, lignoceric acid and nonadecanoic acid, were changed from 5% by mass in previous Examples to 3% by mass or 1% by mass. In the present evaluation, only an effect on smoke flavor inhibition was focused because the amounts of evaporated smoke flavor components are equivalent.

TABLE 2 Type and physical values of acids and evaluation results Acid Dis- Boiling sociation Smoke Content Point constant flavor Acid name [wt %] [° C.] pKa₁ inhibition Example 7 Isoascorbic 1.00 503 4.13 2.0 Example 8 acid 3.00 1.7 Example 6 5.00 1.5 Example 9 Lignoceric 1.00 406 ≈5.00 2.0 Example 10 acid 3.00 2.0 Example 2 5.00 1.7 Example 11 Nonadecanoic 1.00 368 2.0 Example 12 acid 3.00 2.0 Example 4 5.00 1.9

FIG. 5 indicates a graph illustrating the relationship between the acid content and smoke flavor inhibition. From FIG. 5, it may be observed that even when the content is reduced to 1% by mass, the effect of acid is high. This is merely because a highly effective acid can exhibit the effect at a low content. Because acids such as isoascorbic acid, lignoceric acid and nonadecanoic acid have high boiling points, the acids tend to be evaporated by heating, generate aerosol by condensation and remain in particles, and it is predicted that a high effect is obtained because the acids remain in aerosol even after dilution in the oral cavity during smoking. When the acid content is excessive, characteristics of acid may be noticeable, and thus a suitable content may be 10% by mass or less.

Examples 13 to 16, Comparative Examples 22 to 25: Effect by Liquid that Generates Aerosol

The test was carried out in the same manner as in previous Examples and Comparative Examples except that the liquid that generates aerosol was varied. In the present test, the solvents which were liquids that generate aerosol used were, in addition to propylene glycol, glycerol, diacetin and triethyl citrate (TEC), and the acid used was nonadecanoic acid. The results are shown in FIG. 6. When propylene glycol was used, the highest smoke flavor inhibition was obtained and the smoke flavor inhibition was low for other liquids. This indicates that the liquid that generates aerosol which is likely to exhibit the highest effect is propylene glycol, and the present technology is effective when a whole or a small amount of the liquid contained is propylene glycol.

TABLE 3 Type and physical values of liquids that generate aerosol and evaluation results Smoke Content Content flavor Liquid [wt %] Acid [wt %] inhibition Example 13 Propylene 50 Nonadecanoic 5 3.0 glycol acid (addi- Example 14 Glycerol tional 1.3 Example 15 Diacetin amount) 1.3 Example 16 Triethyl 2.5 citrate Comparative Propylene 50 No — 6.0 Example 22 glycol addition Comparative Glycerol 1.8 Example 23 Comparative Diacetin 1.5 Example 24 Comparative Triethyl 3.5 Example 25 citrate

INDUSTRIAL APPLICABILITY

The tobacco filler of the present invention may fill a non-combustion smoking article for smoking. 

What is claimed is:
 1. A tobacco filler for a non-combustion smoking article comprising a shredded tobacco, and a liquid that generates aerosol, wherein the tobacco filler contains an acid that has a first acid dissociation constant of 4.0 to 6.0 inclusive and a boiling point of 366° C. to 600° C. inclusive.
 2. The tobacco filler according to claim 1, wherein the acid is at least one selected from the group consisting of ascorbic acid, isoascorbic acid, heneicosanoic acid, lignoceric acid, octacosanoic acid and nonadecanoic acid.
 3. The tobacco filler according to claim 1, wherein the tobacco filler containing the acid at 0.25% by mass to 10% by mass inclusive of the whole tobacco filler.
 4. The tobacco filler according to claim 1, wherein the liquid that generates aerosol contains propylene glycol (PG). 